Electrodeposition of rhodium (i.e., plated rhodium) has many uses. For example, rhodium is sometimes plated onto jewelry and other decorative items because of its attractive finish. As another example, because of its hardness and resistance to wear, rhodium is sometimes plated onto the wearing surfaces of various tools.
A long known disadvantage to plated rhodium, however, is its inherent high tensile stress. Because of the high tensile stress, plated rhodium often cracks. When plated onto jewelry or decorative items, the thickness of the plated rhodium is typically very thin (e.g., no thicker than 2.5 microns) to avoid cracking. Although there are known methods of plating thicker rhodium (e.g., on the order of 10 to less than 100 microns) using stress reducers in the plating bath to reduce the likelihood that the plated rhodium will crack, the use of stress reducers typically results in plated rhodium that is less hard and less resistant to wear than rhodium plated without the use of stress reducers. In one aspect, the present invention allows for the creation of thicker plated rhodium without substantial cracking. In another aspect of the present invention, the hardness and resistance to wear of the plated rhodium is not significantly diminished.